In Applicants prior application, a least squares circle fitting is used to estimate the radius of a binary pupil disk mask. Using this radius and a similarly derived radius for the iris, an impulse response array is created and used in a matched filter test to determine whether or not a valid pupil is in the image array.
One problem with this approach is that occasionally a portion of the eye, such as the eyelids and/or the white portion of the eye, may have intensity values below a threshold for creating the binary image mask. This may occur if there is low contrast in the image of the eyes. In this instance, those portions of the binary image of the iris or pupil below the threshold register as missing, which in turn reduces the correlation peak below a level necessary to obtain a detection of the pupil from the correlation peak. This results in the eye not being found.
Accordingly, it is one object of the invention to provide a more robust algorithm for reliably finding the eyes of a subject by using a plurality of matched filter tests that each examine a different part of the eyes. It is another object of the invention to provide indications of magnitude of some disease processes of the eyes. It is a further object of the invention to provide a sense of homeostasis of the eyes. Other objects will become apparent upon a reading of the following specification and appended claims.